Bevel, protractor, and square.



PATENTED MAY 28.; 907.

T; W. SPELLMAN. BEVEL, PROTRAGTOR'; AND SQUARE.

APPLICATION FILED 8111 1. 29, 1904.

THOMAS W. SPELLMAN, OF WORCESTER, MASSACHUSETTS.

BEVEL, PROTRAOTOR, AND SQUARE.

Specification of Letters Patent.

Patented May 28, 1907.

Application filed September 29, 1904, Serial No- 226,506-

To on whom it may concern.-

Be it known that I, THOMAS W. SPELLMAN, a citizen of the United States,1 residing at Worcester, in the county of Worcester and State ofMassachusetts, have invented a new and useful Bevel, Protractor, andSquare, of which the following is a specification.

This invention relates to a bevel or tool for laying out angles.

' The especial object of this invention is to provide a compact, simple,efiicient and inexpensive tool for laying out angles when figured to acommon base line. i

A bevel constructed according to this invention has been especiallydesigned for use in marking out pieces of structural iron work or thetemplet boardswhich are used in cutting and drilling the same. To theseends, thisinvention consists of the bevel as an article of manufacture,and of the combinations of parts therewith as hereinafter described andmore particularly pointed out in the claims at the end of thisspecification.

In the accompanying drawing, Figure 1 is a perspective view of a bevelor tool constructed according to this invention. Fig. 2 is a detail viewshowing a slightly modified construction, Fig. 3 .is a fragmentary viewillustrating the character of the work in connection with which thebevel is employed, and Fig. 4 shows the manner of charting or.

. drawing the angle to which a beam or templet-board is to be out.

In cutting to proper length and punching the holes in the pieces orbeams employed in structural iron-work, care has to be exerv cised incutting the ends of the pieces at exactly proper angles. In many classesof structural iron-work, particularly in the construction of trusses andin the construction of bridges, the ends of the beams or pieces have tobe cut at widely varying angles. In laying out work of this character itwas formerly customary to figure these angles in degrees, minutes andseconds. That is to say, these angles were formerly figured to fractionsof a circle, and graduated protractors or arcs were employed in layingout the work. More recently, however, in laying out work of this kind,it has "become a nearly universal custom to figure the different anglesto abaseline of known length. That is to say, in the drawings forstructural iron work the various angles are now ordinarily indicated bymeans of small right-angle triangles, one side the bolt-holes.

of each of which is twelve units in length, while the other side is ofproper length to subtend the desired angle at the apex of the triangle.In laying out work from drawings of this character Where severalduplicated pieces are to be cut and punched, it is cus tomary to make atemplet-board for scribing the ends of a beam or other piece of metal tobe cut, and for marking the s ots for boring Where a sing e piece is tobe cut and punched, the work is sometimes scribed and laid out directlyupon the iron itself. In either case in order to lay out and scribe theproper angle either directly upon the iron or upon the templet-board, itis now customary for the workman to use an ordinary two-foot square,such as employed by carpenters, and to lay a straight edge from thetwelve inch mark on one leg'of the square to a graduation of the propernumber of inches or fractions of an inch upon the other leg of thesquare. From an anglethus determined the workman then usually sets thetipping arm of an ordinary bevel from which the work is scribed toproper scale. In laying out work in this manner the workman employsthree separate instrumentalities, to wit; the square, straight-edge, andbevel, and in the use of these instrumentalities there is a considerableliability of inaccuracy. A tool constructed according to my invention isespecially designed for work of this class, and is intended to give anydesired angle which is figured to a base line by a single, direct andsimple adjustment.

Referring to the accompanying drawing and in detail, a bevel constructedaccording to this invention, as hereln illustrated, comprises a main armor member 10 which is graduated along its edge, and is slotted as at 11.Extending transversely with respect to the slot 11 is an adjusting slot12. ,Longitu dinally movable upon the main graduated arm 10 is a bracketor base-line arm. Extending down from the bracket or base-line arm is aflange 13 which fits into theslot 11, and extending up from the bracketare arms 14 having a pin or screw for pivotally supporting the tiltingarm 15. Threaded into the flange 13 and carrying a clamping Washer is awing-bolt 16. The tilting arm 15 is slotted as at 18, to engage anend-pin or screw 17.

In some-cases where it is desired to provide a construction withoutobstruction on either face, the main graduated arm may be IIOcountersunk or chambered out as at 19, as shown in Fig. 2, to receivethe adjusting wing-bolt 16.

In the construction of a bevel or tool for laying out angles figured toa base line of twelve units, the vertical distance separating the pivotof the tilting member 15 to the base-line arm and the pivotal pointconnecting the tilting arm with the main arm is equal to twelve units ofthe scale to which the main arm is graduated.

' In Fig. 3 a indicates a templet board or the iron itself out off at b,on an angle which is drawn on the chart 0 in Fig. 4.

In the use of the bevel as thus constructed, by sliding the base-linearm to different positions, the angular adjustment of the tilting armmay be made to correspond to any desired angle, for example, if a lengthof four and three-quarters inches is required to sub tend the angleillustrated in Fig. 4, when figured to a base-line of twelve inches, bysetting the base-line arm to the position illustrated in Fig. 1, thetilting arm will be given the required inclination, and the parts may beclamped in this position by the fastening bolt, so that the bevel can bedirectly used for laying out the templet-board or directly upon the ironitself, as desired.

I am aware that numerous changes may be made in the construction of abevel with out departing from the scope of this invention as expressedin the claims. I do not wish, therefore, to be limited to the construction I have herein shown and described, but

What I do claim and desire to secure by Letters Patent of the UnitedStates is 1. As an article of manufacture. a bevel comprising a main armhaving a graduated scale thereon, a base line arm having a slid ingconnection with the main arm and held perpendicular thereto in allpositions there of, means for clamping the base line arm in any positionalong said scale, and a tilting straight edge connected with the end ofthe, base line arm by a fixed pivotal connection and with the end ofsaid main arm by a freely sliding pivotal connection, said base line armhaving a constant unadjustable length equal to a definite andpredetermined number of units ol the scale on the main arm.

2. As an article of mamil acture, a bevel for the linear measurement ofangles, eom-- prising a main arm having graduations and longitudinalslots, an adjusting piece or bracket mounted in said slots, a clamp-nutand screw for holding the adjusting pieee in ditlerent positions, a baseline arm extending from the adjusting piece, a tilting piece or straightedge pivoted to the end ol the base line arm with a pin-and-slotconnection to the main arm, said parts being so proportioned that thedistance from the pivot ol the straight edge at the end ol the base linearm to a line drawn longitudinally with respeet to the main arm throughthe supporting pin of the straight edge will be equal to twelve units ofthe scale of graduations on the main arm.

In testimony whereof I have hereunto set my hand, in the presence ol twosubscribing witnesses.

THOMAS W. SPELLMAX. Witnesses:

PHILIP Sou'rnca'rn, LOUIs W. SOUJIIGA'IE.

